The Bad and RAID

Not perfect though...

One of my pet peeves are IDE connectors placement of
IDE connectors and the ones from the Promise RAID controller could be in a better
location. It'll be hard to use longer or full length PCI cards in PCI slots
3-5 and the IDE cables will probably have to wrap around all the other devices.
We also would have liked to see active cooling on the i845E chipset rather
then just a large heatsink but it really shouldn't make a difference in a
well ventilated case.

A little on RAID...

IDE RAID 0 is not really considered a
true RAID since there isn't any data redundancy. RAID 0 takes two drives of the
same size/configuration and stripes them, meaning it makes one big drive out of
two equal ones. This improves performance by cutting hard drive latency in half.
Since the data is divided equally and written on two hard drives it also
increases the data bandwidth by two. The reason it's not considered true RAID is
because if one drive fails, all data is lost.

IDE RAID 1 on the other hand mirrors two
drives of the same size, so in theory if one drive fails, the other will take
over as the primary hard drive and the system can continue to operate normally.
This is what is supposed to happen with a SCSI hard drive setup and it actually
works pretty well there.

The IDE subsystem doesn't allow hard
drives to be disconnected while the computer is still powered up and in use like
SCSI can unless you have a special HDD tray. Generally, when one IDE drive fails
the system usually locks up anyway. The data is safe since it's mirrored on the
other drive which is the real benefit.

With IDE RAID 0+1, you need four
hard drives of the same configuration/size. What RAID 0+1 does is
stripes two sets of two hard drives, one set for a RAID 0 configuration and the
other for RAID 1. What this does is offer the best of both worlds, the high
performance of RAID 0, with 100% data redundancy of RAID 1. Hence the name RAID
0+1. The only downside would be the need for four identical hard
drives.